Editor crashes when Material Layer visibility is toggled after removing a Material Layer in Parent

When a Material Layer is removed from a Parent Material, the Parent Material updates correctly in the viewport, but any Child Material Instance do not update correctly in the viewport until the Child Material Instance is opened and the Material Layer visibility is toggled. If one of the Child Material Instances was open in the Editor viewport when the Material Layer was removed in the Parent Material, toggling the visibility in the Child Material Instance’s Layer Parameters tab will crash the Editor. This issue doesn’t occur if the Child Material Instance isn’t open in the Editor Material window when the Material Layer is removed from the Parent Material.

1. Open the MAP_MatLayersDebug_A level in the attached project
2. Open the MI_LayeredMat_Parent Material
3. In the Layer Parameters tab, add a Material Layer, set the Layer asset to ML_BasicLayer and the Blend Asset to MLB_BasicLayerBlend
4. Open MI_LayeredMat_ChildA and toggle layer visibility in the Layer Parameters tab.
5. Note that the Parent and ChildA should now should the added Material Layer in the viewport
6. Open the MI_LayeredMat_Parent Material and remove the Material Layer you added
7. Open MI_LayeredMat_ChildA and toggle the visibility of the bottom layer (basic layer)

Expected
Editor doesn’t crash and the removed layer is no longer visible in the Child Material Instance

Actual
The layer that was removed in the Parent Material is still visible in the Child Material and the Editor crashes when the Material Layer visibility is toggled in the Child Material with the error:
{{LogWindows: Error: appError called: Assertion failed: EditorOnly.LayerStates.IsValidIndex(Index) [Link Removed] [Line: 318] }}